AFP Composite Lay-Up Over Unsupported Aircraft Panel Slots

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Solution Overview

Problem

The conventional manufacturing process of aircraft panels using composite materials is complex and time-consuming due to the need for reaction mandrels and auxiliary supports, which increase lead time and recurrent costs while introducing variability and potential errors.

Innovation Solution

A method for automatic lay-up of composite materials directly over integrated components like stringers or frames without auxiliary supports, using optimized tow tension and reduced compaction pressure with AFP machines to ensure accurate deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If reaction mandrels and auxiliary supports are used during AFP machine pressure application, then the composite skin can be properly formed over integrated components, but the manufacturing process becomes complex and time-consuming with increased lead time and costs

Engineering Contradiction:
Improvecomposite skin formation accuracyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the reaction mandrel and auxiliary support tools from the manufacturing process. By directly laying up composite material over the unsupported slot of the integrated component, the patent removes the need for these auxiliary elements, thereby simplifying the manufacturing process while maintaining the ability to form the composite skin accurately

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The integrated component serves itself by providing the necessary support structure without requiring external reaction mandrels. The component's own geometry and the controlled AFP machine parameters enable the composite material to be properly formed directly on the component, making the system self-sufficient

Inventive Principle:
Principle #25Self-service

2Reliability

If reaction mandrels and auxiliary supports are used during lay-up, then proper support is provided during AFP machine pressure application, but lead time and recurrent costs increase

Engineering Contradiction:
Improvesupport stability during depositionVSAvoidlead time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention removes the reaction mandrel extraction step from the process flow. By eliminating this auxiliary element entirely, the patent reduces the number of operations required (placement, positioning, and extraction of mandrels), thereby reducing lead time while maintaining support stability through direct deposition control

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention enables continuous lay-up operation without interruption for mandrel extraction or repositioning. The AFP machine can continuously deposit composite material over the integrated component, maintaining uninterrupted production flow and reducing total manufacturing time

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If reaction mandrels are used to compensate for pressure, then accurate tow placement is achieved, but the process requires precise coordination and handling that introduces variability

Engineering Contradiction:
Improvetow placement accuracyVSAvoidprocess variability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The integrated component provides its own geometric reference and support structure, eliminating the need for separate reaction mandrels that require precise coordination. The component's fixed geometry serves as the reference for tow placement, reducing human intervention and associated variability

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces the mechanical reaction mandrel system with a controlled force application system. By adjusting AFP machine parameters (roller pressure, tow tension, deposition speed), the patent achieves accurate tow placement through controlled mechanical forces rather than physical contact with auxiliary mandrels, thereby reducing coordination complexity and variability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method simplifies the workflow, reduces lead time and costs, enhances flexibility, and maintains product quality by eliminating the need for reaction mandrels and other auxiliary tools.

Implementation Method 1

adjusting the force applied to the tow with the AFP machine during deposition over the unsupported slot to compensate the lack of auxiliary support tools

Methodology Applied
Scientific EffectTension: Tension

Implementation Method 2

reducing a compaction pressure applied to the tow with the AFP machine while increasing the tow tension during deposition over the unsupported slot

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4684946A1Method for automatic lay-up of composite material for aircraft panels
Publication Date: 2026.01.28 AIRBUS OPERATIONS SL
  • EP4684946A1 patent drawingFigure 1
  • EP4684946A1 patent drawingFigure 2
  • EP4684946A1 patent drawingFigure 3~4

AI summary

A method (100) for manufacturing an aircraft panel that comprises a composite skin (240) with integrated components (220) (stringers/frames) having unsupported slots (220a), the method comprising obtaining (110) a male tool with the integrated component (220), laying up (120) the composite skin directly over the unsupported slots of the integrated component (220) with an automated fiber placement, AFP machine that provides tow deposition, wherein the integrated component (220) lack auxiliary support tools and adjusting (130) the force applied to the tow with the AFP machine during deposition over the unsupported slots to compensate the lack of auxiliary support tools.